Electropyrotechnic link

ABSTRACT

An electropyrotechnic link having two connectors held together by a ring of fusible material. When the ring is melted by heat, the two connectors separate. The heat may come from an external source such as a fire or from an electrically activated burner positioned so as to melt the ring if activated.

United States Patent is] 3,660,794 Brizzolara 1 May 2, 1972 [54]ELECTROPYROTECHNIC LINK 1,953,582 4/1934 Belknap l69/42 [72] Inventor:Henry M. Brizzolara, Allentown, Pa. 1l6748l 1/1916 F' 169/42 7 3,118,9941/1964 Kabik ..337/416. [73] Assignee: Atlas Chemical Industries, Inc.,Wilming- DeL Primary Examiner-Bernard A. Gilheany 22 Filed; May 7, 970Assistant Examiner-F. E. Bell pp No 35 493 Attorney-Kenneth E. Mulfordand Roger R. Horton [57] ABSTRACT 52 US. Cl ..337 401 337 405,337 416 EInt Cl H0lh3/7/76 An electropyrotechmc lmk havmg two connectors held[58] ashram '5'5'%'/i"'ili'3'"'i2 183 185, together by a ringoffusiblematerial when the ring is melted 337/298 401, 402 404 4] 1:416, 176 178,407' by heat, the two connectors separate. The heat may come 405 409; 12 2 1 9 42 from an external source such as a fire or from anelectrically activated burner positioned so as to melt the ring ifactivated. 56 R f C't d 1 e erences l 5 Claims, 2 Drawing Figures UNITEDSTATES PATENTS 357,148 2/1887 Hall ..l69/42 P'ATENTEDMAY 21912 I L3,660,794

FIG. I

INVENTOR Henry M Brizzolom BY M ATTORNEY This invention relates to anelectropyrotechnic link which can be actuated either by an external heatsource or by an electrically activated burner.

An electropyrotechnic link is often used in a fire alarm V system todetect heat and set off a sprinkler system or an alarm, close a shutter,or similar function. In the device of the present invention, twoconnectors are held together by a ring of fusible material. When thering melts, the connectors are freeto separate. The electropyrotechniclink of this invention is easy to make and to assemble. Each connectormay be stamped from a single piece of metal and no soldered connectionsare necessary.

FIG. I shows a side view in section of the electropyrotechnic link ofthis invention.

FIG. II shows an isometric view of one of the connectors of theelectropyrotechnic link.

In FIGS. I and II, a connector 1 has a side arm 2 having a slit 3through it. The vertical portion 4 of the connector has burner retainingtabs 5 and 6 and ring retaining tab 7 extending from it. i

In FIG. I, two connectors l are positioned around an electricallyactivated burner 8 which consists of a container 9 having lead wires 10and 11 hermetically sealed with glass 12 at its base. Bridgewire 13joins the two lead wires and is coated with initiating composition 14,for example, barium styphnate, lead azide, lead styphnate,LMNR-chlorate, or zirconium-barium nitrate. Over initiating composition14 is placed burning composition 15, for example, tungsten powder orsilicon-red lead. While the particular burner illustrated in FIG. I ispreferred, other types of electrically activated burners may also beused, Finally, ring 16 holds the two connectors in the position shown inFIG. I and is itself held in place by tabs 7. The ring is of a fusiblematerial, i.e., a material which is melted or destroyed by heat such aslow-melting metals or plastics; Woods metal is preferred.

The electropyrotechnic link is easily assembled by positioning the twoconnectors around the burner and pressing the ring down over thevertical portions of theconnectors until tabs 7, which have been pushedinward by the ring, snap out into place.

Slits 3 may be used to connect the electropyrotechnic device to a tirealarm system or other system. In a fire alarm system, the connectors maybe placed under a spring tension tending to pull them apart. Thus, whenring 16 melts, connectors 2 are pulled apart setting off a sprinklersystem or an alarm. Should it be desirable to activate theelectropyrote'chnic link manually as, for example, when a tire isdetected which has notyet generated enough heat to melt the ring, acurrent may be sent through lead wires 10 and 11, heating bridgewire l3and initiating compositions l4 and 15 thereby melting the ring.

What is claimed is:

1. An electropyrotechnic link comprising A. two connectors each having avertical portion and a side arm extending outwardly from said verticalportion for affixation to an element to be connected,

B. a ring of fusible material positioned over the vertical portion ofeach of said two connectors so as to prevent said connectors from movingapart, and

C. an electrically activated burner positioned so as to fuse said ringwhen activated, thereby permitting said connectors to move apart.

2. The electropyrotechnic link of claim I wherein said burner ispositioned at the center of said ring.

3. The electropyrotechnic link of claim 1 wherein said ring is made ofWoods metal.

4. The electropyrotechnic link of claim 1 wherein said ring is held inplace by tabs extending from the vertical portions of said connectors.

5. An electropyrotechnic link comprising A. an electrically activatedburner having side walls B. two connectors each having a side armextending outwardly in a direction opposite the other from said sidewalls and each having a vertical portion running along said side walls,said vertical portions being generally opposite one another, and

C. a ring of metal, fusible upon activation of said burner, surroundingand holding together said burner and said vertical portions of saidconnectors, said ring being held against movement in one direction alongsaid burner by said side arms and being held against movement in theother direction along said burner by tabs extending outwardly from saidvertical portions of said connectors.

1. An electropyrotechnic link comprising A. two connectors each having avertical portion and a side arm extending outwardly from said verticalportion for affixation to an element to be connected, B. a ring offuSible material positioned over the vertical portion of each of saidtwo connectors so as to prevent said connectors from moving apart, andC. an electrically activated burner positioned so as to fuse said ringwhen activated, thereby permitting said connectors to move apart.
 2. Theelectropyrotechnic link of claim 1 wherein said burner is positioned atthe center of said ring.
 3. The electropyrotechnic link of claim 1wherein said ring is made of Wood''s metal.
 4. The electropyrotechniclink of claim 1 wherein said ring is held in place by tabs extendingfrom the vertical portions of said connectors.
 5. An electropyrotechniclink comprising A. an electrically activated burner having side walls,B. two connectors each having a side arm extending outwardly in adirection opposite the other from said side walls and each having avertical portion running along said side walls, said vertical portionsbeing generally opposite one another, and C. a ring of metal, fusibleupon activation of said burner, surrounding and holding together saidburner and said vertical portions of said connectors, said ring beingheld against movement in one direction along said burner by said sidearms and being held against movement in the other direction along saidburner by tabs extending outwardly from said vertical portions of saidconnectors.